Year	Years
1970	1.07
1971	1.1
1972	1.14
1973	1.18
1974	1.21
1975	1.25
1976	1.29
1977	1.34
1978	1.38
1979	1.43
1980	1.48
1981	1.53
1982	1.58
1983	1.63
1984	1.69
1985	1.75
1986	1.81
1987	1.88
1988	1.94
1989	2.02
1990	2.09
1991	2.17
1992	2.25
1993	2.34
1994	2.43
1995	2.53
1996	2.65
1997	2.77
1998	2.9
1999	3.02
2000	3.14
2001	3.27
2002	3.39
2003	3.51
2004	3.64
2005	3.76
2006	3.89
2007	4.01
2008	4.14
2009	4.26
2010	4.39
2011	4.51
2012	4.64
2013	4.76
2014	4.89
2015	5.01